A new acetylated spirostanol saponin and other constituents from the rhizomes of Dioscorea althaeoides R. Knuth (Dioscoreaceae)

Abstract A new acetylated spirostanol saponin ( 7 ), dioscin-6′- O -acetate, was isolated from the rhizomes of Dioscorea althaeoides R. Knuth (Dioscoreaceae), together with fourteen known compounds, including three spirostanol saponins ( 1 – 2 , 6 ), three furostanol saponins ( 10 – 12 ), one diarylheptanoid ( 3 ), three sterols ( 4–5 , 9 ), three aliphatic acids ( 8 , 13 – 14 ) and one aliphatic alkane ( 15 ). Their structures were established by extensive 1D- and 2D- NMR (DEPT, 1 H– 1 H COSY, HSQC, HMBC and NOESY) experiments in conjunction with IR and HRESI/TOF-MS data, as well as the results of acid hydrolysis. The compounds ( 3 – 8 , 10 – 15 ) were isolated from this species for the first time. The chemotaxonomic significance of these compounds was also discussed